1. Field
Devices consistent with exemplary embodiments relate to optical devices including a three-coupled quantum well structure, and more particularly, to optical devices including a three-coupled quantum well structure having asymmetric multi-energy levels, in which a driving voltage of the three-coupled quantum well structure may be reduced while maintaining a high light absorption intensity.
2. Description of the Related Art
Three-dimensional (3D) cameras may measure a distance to multiple points on a surface of an object. Various algorithms have been proposed to measure a distance between an object and a 3D camera, and a time-of-flight (TOF) algorithm is widely used. According to the TOF algorithm, an illumination light is irradiated to an object and then a TOF taken by the illumination light reflected from the object to be received by a light-receiving unit is measured. The TOF of the illumination light may be obtained by measuring a phase delay of the illumination light, and an optical modulator is used to measure the phase delay.